High reliability wafer level semiconductor packaging

ABSTRACT

Implementations of semiconductor packages may include: a semiconductor wafer, a glass lid fixedly coupled to a first side of the semiconductor die by an adhesive, a redistribution layer coupled to a second side of the semiconductor die, and a plurality of ball mounts coupled to the redistribution layer on a side of the redistribution layer coupled to the semiconductor die. The adhesive may be located in a trench around a perimeter of the semiconductor die and located in a corresponding trench around a perimeter of the glass lid.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to U.S. Provisional Application No.62/296,435, filed on Feb. 17, 2016, entitled “High Reliability WaferLevel Semiconductor Packaging,” invented by Yu-Te Hsieh, and isincorporated herein by reference and priority thereto for common subjectmatter is hereby claimed.

BACKGROUND

1. Technical Field

Aspects of this document relate generally to semiconductors such as chipscale packages and through silicon via packages.

2. Background Art

Conventionally, to connect a glass lid to a semiconductor package,ultraviolet light curable resin and a solder mask is used on the surfaceof the wafers. The resin seals the wafers together and the solder maskprotects the package from temperature cycles, air, and moisture.

SUMMARY

Implementations of semiconductor packages may include: a semiconductorwafer, a glass lid fixedly coupled to a first side of the semiconductordie by an adhesive, a redistribution layer coupled to a second side ofthe semiconductor die, and a plurality of ball mounts coupled to theredistribution layer on a side of the redistribution layer coupled tothe semiconductor die. The adhesive may be located in a trench around aperimeter of the semiconductor die and located in a corresponding trencharound a perimeter of the glass lid.

Implementations of semiconductor packages may include one, all, or anyof the following:

The adhesive may be selected from the group consisting of thermalcurable resin, epoxy, ultraviolet light curable resin or any combinationthereof.

Implementations of a semiconductor package may be manufactured usingimplementations of a method of making semiconductor packages. The methodmay include providing a semiconductor wafer and a glass wafer, forming atrench around a perimeter of one or more semiconductor die of thesemiconductor wafer and forming a trench corresponding with the trenchformed around the perimeter of the one or more semiconductor die in theglass wafer. The method may also include applying adhesive into thetrench of the semiconductor wafer and into the trench in the glasswafer. The method may also include coupling the glass wafer to thesemiconductor wafer by aligning the trench of the semiconductor waferwith the trench of the glass wafer and using the adhesive in thetrenches to bond the semiconductor wafer to the glass wafer, the glasswafer forming one or more corresponding lids for the one or moresemiconductor die. The method may also include singulating the one ormore semiconductor die and the corresponding one or more lids at thetrench in the semiconductor wafer to form one or more semiconductorpackages. The method may also include coupling a redistribution layer toeach of the one or more semiconductor packages. The method may alsoinclude coupling a plurality of ball mounts to each redistribution layerof the one or more semiconductor packages.

Implementations of a method for making semiconductors may include one,all, or any of the following:

The trenches may be formed through one of stencil printing, sawing,lasering, wet etching, dry etching or any combination thereof.

The adhesive may be applied by one of dispensing, spin coating,lithography, spray coating, stencil printing or any combination thereof.

The adhesive may be partially cured before coupling the glass wafer tothe semiconductor wafer.

The glass wafer may be coupled to the semiconductor die using one ofheat compression, ultraviolet light exposure and any combinationthereof.

Semiconductor package implementations disclosed herein may bemanufactured using another method of manufacturing a semiconductorpackage. The method may include providing a semiconductor wafer and aglass wafer, forming a trench around a perimeter of one or moresemiconductor die of the semiconductor wafer and forming a trenchcorresponding with the trench formed around the perimeter of the one ormore semiconductor die in the glass wafer. The method may also includeapplying adhesive into the trench of the semiconductor wafer and intothe trench in the glass wafer. The method may also include coupling theglass wafer to the semiconductor wafer by aligning the trench of thesemiconductor wafer with the trench of the glass wafer and using theadhesive in the trenches to bond the semiconductor wafer to the glasswafer, the glass wafer forming one or more corresponding lids for theone or more semiconductor die. The method may also include singulatingthe one or more semiconductor die and the corresponding one or more lidsat the trench in the semiconductor wafer to form one or moresemiconductor packages.

Implementations of a method for making semiconductors may include one,all, or any of the following:

The trenches may be formed through one of stencil printing, sawing,lasering, wet etching, dry etching or any combination thereof.

The adhesive may be applied by one of dispensing, spin coating,lithography, spray coating, stencil printing or any combination thereof.

The adhesive may be partially cured before coupling the glass wafer tothe semiconductor wafer.

The glass wafer may be coupled to the semiconductor die using one ofheat compression, ultraviolet light exposure and any combinationthereof.

The foregoing and other aspects, features, and advantages will beapparent to those artisans of ordinary skill in the art from theDESCRIPTION and DRAWINGS, and from the CLAIMS.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations will hereinafter be described in conjunction with theappended drawings, where like designations denote like elements, and:

FIG. 1 is a side view of a conventional chip scale package;

FIG. 2 is a side view of a conventional through silicon via package;

FIG. 3 is a side view of a conventional chip scale package with a soldermask;

FIG. 4 is a side view of an implementation of a semiconductor packageformed using adhesive in a trench around the perimeter of thesemiconductor.

FIG. 5A-5E shows various processing steps involved in an implementationof a method for making a semiconductor package.

DESCRIPTION

This disclosure, its aspects and implementations, are not limited to thespecific components, assembly procedures or method elements disclosedherein. Many additional components, assembly procedures and/or methodelements known in the art consistent with the intended semiconductorpackage and method for making a semiconductor package will becomeapparent for use with particular implementations from this disclosure.Accordingly, for example, although particular implementations aredisclosed, such implementations and implementing components may compriseany shape, size, style, type, model, version, measurement,concentration, material, quantity, method element, step, and/or the likeas is known in the art for such semiconductor packages, and implementingcomponents and methods, consistent with the intended operation andmethods.

FIG. 1 illustrates an implementation of a conventional chip scalepackage (CSP) 2. In this implementation, the CSP 2 is formed by couplingthe glass lid 4 to the die 6 with an adhesive 8. In this example theadhesive is an ultraviolet (UV) curable resin 8. A solder mask 10 isthen coupled/applied to the die to protect the die from environmentalstress and eliminate the risk of delamination. The solder mask 10 and UVresin 8 are cured through the glass lid after the glass lid and die havebeen coupled together. In this implementation, there has been observedto be a high rate of delamination where the glass lid 4 separates fromthe die 6, as the semiconductor package 2 is exposed to electricalcurrent. Referring to FIG. 2, an implementation of a conventionalthrough silicon via (TSV) package 12 is illustrated. Here, the glass lid14 and die 16 are covered with a dry film solder mask 18. The throughsilicon vias 20 that are connected to the redistribution layer 22 arealso illustrated.

Referring to FIG. 3, a conventional CSP with solder mask moisturebarrier is illustrated 24. This represents an improvement over thetraditional CSP (FIG. 1) because the solder mask 26 covers the edge ofthe package 28 and die 30, where the glass lid and die meet, prior tosingulation. This extra overlap helps to create a moisture barrier.However, to be implemented conventionally, this method needs thesymmetrical design of aluminum pads at the four sides of the package andneeds wide scribe line spaces for tapper structures at the package edgewhich decreases the gross die per wafer (GDPW) possible.

Referring to FIG. 4, an implementation of a semiconductor package 32using a trench 34 is illustrated. The semiconductor die 36 is fixedlycoupled on the first side to a glass lid 38 by an adhesive. The adhesiveused may be, by non-limiting example, thermal curable resin, epoxy,ultraviolet light curable resin any combination thereof, or any othermaterial capable of bonding the die to the glass lid. A redistributionlayer 36 is coupled to a second side of the semiconductor die 32. Theredistribution layer serves to route pads/balls on the semiconductor dieto connectors that will be present on the circuit board to which thesemiconductor package will ultimately be attached. A plurality of ballmounts 38 are coupled to the redistribution layer 36 on a side of theredistribution layer 36 opposing the side of the redistribution layer 36coupled to the semiconductor die 32. The adhesive is located in/placedin a trench 34 around a perimeter of the semiconductor die 36 and isalso located in/placed in a corresponding trench 34 around a perimeterof the glass lid 38. The adhesive present in the trench 34 formed fromcombined trenches in the glass lid 38 and the die 36 may form a hermeticseal and thereby prevents delamination. The increased strength of thebond between wafers may allow for chip stacking at any desired height ofstacked chips.

Referring to FIGS. 5A-5E, a method for making a semiconductor packageimplementation is illustrated. In FIG. 5A, a glass wafer 42 and asemiconductor wafer 44 with active areas 46 are provided as illustrated.Referring to FIG. 5B, the formation of corresponding trenches 50 on theglass wafer 42 and semiconductor wafer 44 is illustrated. The trenchesmay be formed through one of stencil printing, sawing, lasering, wetetching, dry etching, any combination thereof or any other process thatis capable of forming a trench-like structure in glass or semiconductormaterials. Adhesive 48 may then be deposited into the correspondingtrenches 46. The adhesive 48 may be any disclosed in this document. Theadhesive 48 may be applied using, by non-limiting example, dispensing,spin coating, lithography, spray coating, stencil printing, spinetching, spray etching, any combination thereof, or any other processdesign to get the adhesive into the trench of the glass lid and/orsemiconductor die. In some implementations, the method may includepartially curing the adhesive 48 before coupling/bonding the glass wafer42 to the semiconductor wafer 44.

In various implementations coupling/bonding of the glass wafer 42 and 44may be accomplished by using, by non-limiting example, compression,heated compression, ultraviolet light exposure, curing, and combinationthereof, or any other method of bonding two surfaces together. In someimplementations, the surface energies of the exposed surfaces of the twowafers 42, 44 may be such that they bond when brought into contact witheach other. During coupling/bonding of the glass wafer 42 and thesemiconductor wafer 44, the trench of the semiconductor wafer 44 isaligned with the trench of the glass wafer 42. This may allow theadhesive present in the trenches to bond the semiconductor wafer 44 tothe glass wafer 42, thereby forming one or more corresponding lids forthe various one or more semiconductor die on the semiconductor wafer 44.In various implementations, all of the one or more semiconductor die mayhave the same size, or in others, one or more of the die may havedifferent sizes/dimensions from other semiconductor die on thesemiconductor wafer 44. In these implementations, the pattern oftrenches in the glass wafer 42 may be altered to correspond with thepattern of trenches in the semiconductor wafer 44.

Referring to FIG. 5C, the effect of wafer bonding is illustrated whereinthe glass wafer 42 and semiconductor wafer 44 are coupled together. Inthis implementation the adhesive 48 distributes evenly in the trenches50 and between the wafers 42 and 44. In other implementations, theadhesive 48 may be distributed more in one side of the trenches 50 thanthe other. Thinning of the semiconductor wafer 44 is also illustrated.Thinning can be performed by any methods known in the art, such as, bynon-limiting example, backgrinding, polishing, lapping, chemicalmechanical polishing, etching, any combination thereof, and any othermethods of thinning a planar surface. Through silicon vias 52 may alsobe added to the semiconductor wafer 44. The various process steps usedto form the through silicon vias may include, by non-limiting example,etching of the semiconductor wafer, formation of adhesion films insidethe various vias, electroplating/electroless plating within the vias toform a contact, formation of pads, and those other process steps andprocesses capable of constructing a via through the thinned wafer.

Referring to FIG. 5D, singulation of the semiconductor package 54 isillustrated. Here, the singulation is performed in the middle orsubstantial middle of the corresponding trenches 50, or the bond line,so each package has 50% or substantially 50% of the bond line.Singulation may take place using, by non-limiting example, sawing,lasering, high pressure water jet cutting, etching, or any other processfor separating the semiconductor packages. Referring to FIG. 5E, animplementation of the completed singulated package is shown 52. Invarious method implementations, the method may include coupling aredistribution layer 56 to each of the singulated semiconductorpackages. In various implementations, the method may also includecoupling a plurality of ball mounts to each redistribution layer of eachof the singulated semiconductor packages. In various implementations,balls may be coupled to the ball mounts to form a ball grid array 60. Inparticular implementations, the method may include adding a solder mask58 may be added to the package.

The various methods of manufacturing a semiconductor packages disclosedherein may improve the reliability of the package for application inautomotive applications. Semiconductor packages manufactured using thedisclosed methods and structures may demonstrated increased adhesionforce against the stress in the X-axis and the Y-axis during thermalshock reliability testing. The trench process on the silicon wafer andthe glass wafer may also let the dam adhesive fill the gap withoutneeding any changes to the design rules or use of wide scribe lines,thus maintaining the same gross die per wafer performance.

In places where the description above refers to particularimplementations of semiconductor packages and implementing components,sub-components, methods and sub-methods, it should be readily apparentthat a number of modifications may be made without departing from thespirit thereof and that these implementations, implementing components,sub-components, methods and sub-methods may be applied to othersemiconductor packages.

1. A semiconductor package comprising: a semiconductor die; a glass lidfixedly coupled to a first side of the semiconductor die by an adhesive;a redistribution layer coupled to a second side of the semiconductordie; and a plurality of ball mounts coupled to the redistribution layeron a side of the redistribution layer opposing the side of theredistribution layer coupled to the semiconductor die; wherein theadhesive is comprised in a trench in the semiconductor die at aperimeter of the semiconductor die and comprised in a correspondingtrench in the glass lid at a perimeter of the glass lid.
 2. Thesemiconductor package of claim 1, wherein the adhesive is selected fromthe group consisting of thermal curable resin, epoxy, ultraviolet lightcurable resin and any combination thereof.
 3. A method for making asemiconductor package, the method comprising: providing a semiconductorwafer and a glass wafer; forming a trench around a perimeter of one ormore semiconductor die of the semiconductor wafer; forming a trenchcorresponding with the trench formed around the perimeter of the one ormore semiconductor die in the glass wafer; applying adhesive into thetrench of the semiconductor wafer and into the trench in the glasswafer; coupling the glass wafer to the semiconductor wafer by aligningthe trench of the semiconductor wafer with the trench of the glass waferand using the adhesive in the trenches to bond the semiconductor waferto the glass wafer, the glass wafer forming one or more correspondinglids for the one or more semiconductor die; singulating the one or moresemiconductor die and the corresponding one or more lids at the trenchin the semiconductor wafer to form one or more semiconductor packages;coupling a redistribution layer to each of the one or more semiconductorpackages; and coupling a plurality of ball mounts to each redistributionlayer of the one or more semiconductor packages.
 4. The method of claim3, wherein the trenches are formed through one of stencil printing,sawing, lasering, wet etching, dry etching and any combination thereof.5. The method of claim 3, wherein the adhesive is selected from thegroup consisting of thermal curable resin, epoxy, ultraviolet lightcurable resin and any combination thereof.
 6. The method of claim 3,wherein the adhesive is applied by one of dispensing, spin coating,lithography, spray coating, stencil printing and any combinationthereof.
 7. The method of claim 3, further comprising partially curingthe adhesive before coupling the glass wafer to the semiconductor wafer.8. The method of claim 3, further comprising coupling the glass waferand the semiconductor wafer using one of heat compression, ultravioletlight exposure, and any combination thereof.
 9. A method for making asemiconductor package, the method comprising: providing a semiconductorwafer and a glass wafer; forming a trench around a perimeter of one ormore semiconductor die of the semiconductor wafer; forming a trenchcorresponding with the trench formed around the perimeter of the one ormore semiconductor die in the glass wafer; applying adhesive into thetrench of the semiconductor wafer and into the trench in the glasswafer; coupling the glass wafer to the semiconductor wafer by aligningthe trench of the semiconductor wafer with the trench of the glass waferand using the adhesive in the trenches to bond the semiconductor waferto the glass wafer, the glass wafer forming one or more correspondinglids for the one or more semiconductor die; and singulating the one ormore semiconductor die and the corresponding one or more lids at thetrench in the semiconductor wafer to form one or more semiconductorpackages.
 10. The method of claim 9, wherein the trenches are formedthrough one of stencil printing, sawing, lasering, wet etching, dryetching and any combination thereof.
 11. The method of claim 9, whereinthe adhesive is selected from the group consisting of thermal curableresin, epoxy, ultraviolet light curable resin and any combinationthereof.
 12. The method of claim 9, wherein the adhesive is applied byone of dispensing, spin coating, lithography, spray coating, stencilprinting and any combination thereof.
 13. The method of claim 9, furthercomprising partially curing the adhesive before coupling the glass waferto the semiconductor wafer.
 14. The method of claim 9, furthercomprising coupling the glass wafer and the semiconductor wafer usingone of heat compression, ultraviolet light exposure, and any combinationthereof.